Research On Signal Detection Algorithm Based On The Hybrid Algorithm In MIMO-OFDM System

MIMO-OFDM system has many advantages, such as improving the rate of datatransmission effectively and increasing the spectrum utilization. Therefore it has become apotential kind of technology in the development of mobile communication in the future. Theperformance of the MIMO-OFDM system largely depends on the performance of the detectorat the receiving end. So it need strike a balance between the complexity of the detectionalgorithm and the detection performance. This is to say, the detection performance of thedetector should be improved under the condition of reducing the algorithm complexity as lowas possible.The basic model and the advantages of MIMO-OFDM system are introduced in thepaper. On the basis of using V-BLAST decoding structure, it introduces the theory andcompares the simulation of several basic detection algorithms at the receiving end. Thedetection performance of the optimal detection algorithm is the best among the lineardetection algorithm and nonlinear detection algorithm. But its complexity is higher than thelinear detection algorithm. At the same time the detection performance of the linear detectionalgorithm is the worst among the three algorithms and the nonlinear detection algorithm isrelative in the middle. Because basic QR algorithm can not make full use of the MIMOsystem diversity gain of each layer. A QR detection algorithm based on sorting is proposed inthe paper. This algorithm well reduces the error of the first detecting layer. By comparing theperformance of cyclic iteration QR detection algorithm and sorted QR detection algorithm, itconcludes that the performance of cyclic iteration QR detection algorithm is better. In thecyclic iteration QR detection algorithm, the first two layers will bring some iteration error forthe subsequent testing layer during the QR detection for the first time. Therefore a paralleliteration QR detection algorithm and a maximum likelihood cyclic iteration QR detectionalgorithm are proposed in the paper. Parallel iterative QR detection algorithm ensures theaccuracy of the initial detection layer in the QR detection for the first time. Maximumlikelihood cyclic iteration QR detection algorithm ensures the lowest interference in the QRdetection for the first time. The interference is brought by the first two layers for thesubsequent testing layer. The improved algorithm can well improve the performance of thedetector under the condition of low algorithm complexity.